Route-selecting automatic telephone system



June 16, 1953 F. P. GoHoRl-:L

ROUTE-SELECTING AUTOMATIC TELEPHONE SYSTEM 3 `Sheets-Sheet 1 Filed oct. 8, 194'/ INVENToR. 5f/PMN@ P/fR/Pf 60mm BYr June 16, 1953 F. P. Gol-lonen.

ROUTE-SEIECTING AUTOMATIC SYSTEM Filed Oct. 8. 1947 3 Sheets-Sheet 2 l I lu n L INVENTOR. FER/MND HEP/PE Gow/Pfl ATMP/v June 16, 1953 F. P. GoHoRx-:L

ROUTE-SELECTING AUTOMATIC TELEPHONE SYSTEM s sheets-sheet s Filed OCT.. 8, 1947 INVENTOR. FMA/HND PIER/Pf GDM/PEL 3 the following description given as an example without limitation.

Fig. 1 shows an arrangement of selectors according to the invention.

Selectors SI I, SII, SI2, S'I2 of the rst selection stage are assumed to have four output levels c which each comprise four lines that give access to the selectors of the second stage'. They are ,v

distributed in twomultipling groups.

Selectors SZI, S'2I, S22 and S2 2 andfiour other switches, not shown, form the second stage. They areassumed to have four output levels, each comprilsing four outgoing lines, and Jthey arev distri- Y buted in four multipling groups '(two nt shown).

It v'cari be seen that each level of the r'st selectors has access to four second selector groups comprising four lines at each level. Eachincoming line of the first selectors accordingly has access to 16 outgoing lines of the second selectors.

To each of the groups of outgoing lines of the jsecond selectors there are associated marking devices such as IJI, B2, D3, 04, which serve for marking a-i'lctitious occupation of the second selectors when all the lines of an outgoing group are occupied and when a first selector is hunting a line in the said group.

Fig. 2 is a schematic of an assembly of iirst and second selectors. VOnly the members necessary for understanding the invention are shown.

^ It isassumedthat the second selectors comprise four groups jof outgoing lines. The availability of the first two groups is indicated by a negative orpositive polarity on wire t2 that is particular to each of them, or by an alternating polarity that is common to the two groups; the availability of the lsecond two groups is'indicated by a negative or positive polarity on wire tI that is particular to each of them, or by an alternating polarity that is common to the two groups.

When at least one line is idle in the first group of outgoing lines and all the lines of the second group are busy, relayl is energized and relay 02 is in the resting position, and the negative polarity of battery B2'is applied to contact t2 of the jbank associated with wiper T2 over; R021, VTII I, resistance RI and R86.

When at least one line vis idle in the second group and all those of the rst group are busy, relay 02 is excited and relay 0I is in the resting position. The positive polarity of battery BI is applied to bank conta-ct t2 over: T022, RDI I, resistance RI and R86. i When -at least one line is idle in each of the first and the second groups, relays I and U2 are energized. The alternating polarity of generator Ge is applied to bank contact t2 over: TDZI, TlLresistanceRI andRBG. ,Y

In similar manner, a negative, positive or alternating polarity is applied to bank contact tI depending upon whether only relay 03 is energized, only relay 04 is energized or both relays `02 and 04 are energized.

When selector, SI is seized by a call, the various seizure operations take place by one of the known methods. .Relay I pulls up and at TI2 closes the circuit of impulse receiving relay 3'. These impulses eiect in marker MI the steering of sequence switch S which, in the illustrated example, may take up one of the positions 1 to 12. It is assumed that the rst selectors comprise three groups of outgoing lines, Vthe steering being effected by the selective combinations 1 to 4 for the rst group, the selective combinations'r to 8 for the second group, and the selective combinations 9 to 12 for the third group. Y

It is assumed that sequence switch S has been steered to the first position and that there is at least one idle line in the firstgroup of outgoing lines of the second selectors. A- negative or alternating polarity is applied to t2.

The circuit of electromagnet R and of the wipers of selector SI having been completed at TI I, these wipers will advance until the moment when wiper T2 reaches contact t2. The circuit of stop relay 4 is completed over: ground, TI3, wiper C, and one of the bank contacts that correspond toth'e irst group of outgoing lines of the first selector, bank contact and wiper Sd of S, windings-of relay li in series, rectier Rdi, back contact and wiper Sc of S, TIB, Wiper T2 and negative polarity on t2.

At RAI, relay li opens the circuit of electromagnet R, thus causing Si to stop.

At T4I, it completes the circuit of relay 5 which closes at T52 the circuit of relay B to the top wire A. At T43, relay d applies a ground across wiper Sb to testing wire TI, which is not used for the'steering in the case in question, in order to mark the said testing wire busy andY to prevent the stoppage of a second' selector that would proceed to hunt inV either the third or fourth group of lines.

Relay 'I of S2 becomes venergized in serieswith relay 6 of SI. rlhis latter does not become energized, owing tov the high resistance of relay 1.

Selector S2 has now to be steered to an idle line in the group of lines that corresponds to the position of sequence switch S of marker MI..

For thisl purpose, arrangements are provided inassociation with the bank of wiper Sa of S, and depending on the orientation of S, for applying to the bottom wire B, when T53 is closed, either no ground, or a ground across a high value resistance R3+R4, ora ground'across low value resistance R6, or a general ground, these various electric states characterizing the group ofoutgoing lines of the S2 selectors.

In the marker M2 of selector S2 there are pro vided three relays 3,k It and II, vhich are mounted in series andwhich have such characteristics that, 'according to the electric state of Wire' b, either'non'e of them is energized'or only'relay 9, or relays E! and I, or relays 9, I0 and II.

In the case under consideration, when S lof MI stops at position 1, no ground is applied by Sa to the bottom wire B. The three relays 9, IIB and I I of M2 will accordingly remain in the resting position, and stop relay I2 willremain connected to the pilot wire ofthe firstgroup of outgoing lines.

When the circuit ofv rotating electromagnet R of S2 is completed at T'II, the .wipers of S2 advance step byf step.V When they reach the bank contacts of an idle line, the followingfcircuit is completed:y batteryresistance R5, bank contact and Wiper T, T73, wiper C, pilot Wire, RQI, RIIII, RHI, series Windingsof relay I2, ground. Relay I2 becomes energizedland at RI2Iit opens the circuit of R'. Selector S2 stops at the respective position. AtjTI2I,.relay I2 completes through T'M the circuit of relay 8 which becomes energized, and at' TI22 it short-circuits its lefthand winding to mark the occupation.

When wiper A of S2 reaches an idle line, the circuit of relay 63er" SI is completed over relay I3 of the next S2 selector. This relay i3 becomes energized and Vat TI Yit completes TI4 the circuit of relay 2, Whichbecomes energized and closes at T22 its holding circuit on the testing wire over aground in the preceding'Sl selector. At R21,

back and this releases marker MI at T24 and T26 it applies a ground to test Wires' TI and T2' in order to maintain the ocupation coinpleie the holding' circuitof relay a of s2; and at T2I land T23 it connects the talking iiit to selector S2.

Relay 8, which has becomeenergied as mene tioned above, completes at T82 yand T86 its lieldj-y ing circuit; at' R87, it lopensv the circuit of rela-y I which falls back and releases iarli" M2; at TSI and T83 it connects the talking circit to* the next selector. 4 The talking circuit is completed over selectors Si and S2. v

Upon termination of the all, the circuit of 'ife-4 lay 2 is opened, and this effects the rele selector Sil Aand the lopening of the t of relay a which fails back' and releases adottarsi. The steering of selectors SI and S2 for 'the various' positions orgs is uiie in the already de:

scribed manner either over testing' vlie TI oi' testing Wire T2. l Y

Fig. 3 shows a. variant o the veinlcl'odiinent of Fig. 2 in Which there is provided a frequency that is characteristic of eachof the groups of lines outgoing from S2, this frequency being super; posed on the availability Vpoter'itial of selector 'S2.

`It is Iassumed that a frequency fl is applied to wire IUD when at lea'stone idle line Vis.available in the rst group, and frequencies f2 for 'the seond group, f3 for the third f4 for the' fourth.'v

These various freduenciesinay'be applied'iniultaneously. l n

In marker MI of SI, vbald-pass 'filters F'I, F2, F3, Fd are disposed on the Contact baiikfsoi' Wiper Sa, and these lte's penitpassag'e of the respective frequency currents ffl, f2, f3 and T4.

When sequence svvtchvS is steered to' the come bination that corresponds to the Wanted group, stop relay A is connected in series with the band-pass lilter tuned to the frequency that characterizes the said group.

When the Wipers of SI reach an idle line, the circuit of relay l is completed: groundyvvinding of one of the lters FI to F4, condenser CI, segment Slo and pilot Wire; Wiper C, TI3, Wiper T, R82, condenser C2 and one of the generators JI to f4.

Relay it becomes energized and at T112 closes: the circuit of relay 6 and ofthe right-handwinding of relay 5 which was already energized over' TI 5 in its left-hand Winding; and at R4I it opens the circuit of advancing electromagnet R., thusY eiTecting the stoppage of SI at the respective position.

At RSI, relay 6 makes a second break inthe circuit of R; at T62 it closes its holding circuit; and at TSI it prepares the circuit of relay 2, which is completed when relay 5 falls back, as its two windings are in opposition.

Relay 2 becomes energized; at T22 it closes its holding circuit over the preceding selector; at T2I and T25 it closes the talking circuit to selector S2; at T23 it applies a general ground to wiper T to mark the occupation; and at R26 it opens the circuit of relay I which falls back, releasing marker MI.

Selector S2 operates from then on as al selector of an already known type and it receives the selective combination on relay Il directly from the register that controls the forwarding of the call.

t is to be noted that when the Wipers of SI pass over a busy line, stop relay 4 is short-cirl cuitd the''groundV applied'to the corr-- tacts of the lsaid line, e. g. by contact T23.

Ilclai'm; f l. In an autmatie telephone system in which a plurality of -rst and `second selectors and out.

going-trunksar'e provided and. the access .to said outgoing trunks isincreas'ed by distributing .the tiunks'from-a given level .0f the rst selectors over groups of second selectors, each of which has access to different outgoing vtrunks at a given level,- and in 'which means is provided for seizing one of said 'first selectors, the combination .comprising a n'rst marker adapted to be set in response to incoming pulses received by a seize-d rst selector to register avcalled number, sources of signals, means-controlled by the idle or busy condition of the outgoingtrunks .for applying signals-from said sources Yto test 'terminals-.of said seized nrst selector, said signalsindicating which groups'of said outgoing trunks, Y'available to 'said first vselector through second selectors, have at least one idle outgoing trunk, 4means for starting a hunting l'o'pera'tioi'i of said first selector inv vresponse tto the seizure thereof, means in said first marker responsive to said signaleren causing said iir'st selector to vstop vwhen rthe Wipers 'thereof 'rest yon terminals yhaving' access through a second selector lto 'a desired group foi outgoing trunks 'containing an idle outgoing trunk and thus to seize -a second selector, 4a second marker connected 'to the thus selected terminals of said seized irst selector, vandr-neans. in said nrstma'rker and controlled by the Asetting thereof Ifor 'causing lsaid second marker to -mark the desiredgr'oup of trunks in `the terminals ofjsaid seized second selector.,

bination according to claim '1, in which the trunks' leading ,from l'first selectors have' test 'terminals in the nr'stiselectors, and `inv `which the means for applying to the terminals of the nrst selectors comprises a plurality "of 'chain relays, one foreach group of outgoing trunks fromfthe second selectors, vmeans for holding each oi said relays operated untiljall'the outgoing 'trunks of the corresponding gro'ur'n iare busy, sources fof signals/and meansunder control of said relays for connecting signals from s'ai-d'sources to vthe test terminals/of the rst lselectors "to A'indica-'te the conditinofthe'second selectors. 3. In 'an automatic `telephone systemf-the cornbination, acc'ording'to claim 2 `,-in which ythe means: under `control 'of the `chain relays r`conneet 'thes'ign'als toV 'the testv terminals o'f rst selectors leading to second selectors vin which there are idle outgoing trunks in va group and disconnect the signals from test terminals of first selectors leading to second selectors when the outgoing trunks of a group are completely occupied.

4. In an automatic telephone system, the combination according to claim 1, in which the rst selectors have test wipers arrangedl to contact the test terminals'of the trunks and each test wiper of the first selector is arranged to test two groups of second selectors, and in which the means for applying signals to the test terminals ofV the nrst selectors leading to one group of second'selectorshaving an available idle trunk include means to apply a positive potential to said terminals, to apply a negative potential to the test leads of the ,other group of selectors having an available idle trunk, and to apply an alternating potential to the test leads of both groups of second'selecto'r's whentheysimultanously have idle trunks. 1

5. In an automatic bination, accordingY to claim 1, in which the means for causing the second marker to mark the desired group of trunks comprises a plurality of relays in saidy second marker connected in series and to said first marker through said first selector and having diierent marginal operating voltage valuesY whereby they are arranged for selective operation by said first marker dependent on the voltage applied therefrom, and a control relay in said second marker for controlling the second selector in selecting the marked group. Y

6. In an automatic telephone system, the combination, according to claim 1, in which the first selectors -have wipers and the first marker includes a relayand two rectiflers, the rectiers being connected in parallel and in series with the winding of said relay, the operating circuit of vsaid relay being connected to a Wiper of eachof. said rst selectors, whereby a marking potential applied to a terminal of one of said rst selectors will operate said relay, and means for stopping said selector when said relay operates.

7. In an automatic telephone system, the combination, according to claim 1, in which is further. provided a plurality of sources of alternate ing potentials of diierent frequencies, and in which the means for applying signals indicating the groups containing idle trunks comprises a plurality of chain relays, means for causing said relays to mark the terminals of the idle second selectors having access to trunk groups having at least one idle trunkY by connecting thereto-an alternating potential of ak given frequency from'oneof said sources, 'there being ak given frequencyuor combination' of` l'frecl'nien'cies' for each groupuof trunks to ,wh'ichrfthe'second selector lhas access.

8. In an automatic telephone system, tlleicom-l bination,v according 4to claim'7', in which (test wipers are provided for said rst'selectors' and Y the nrst'marker is provided witha test relay,

a sequence switch connectedv in the circuit thereor", and a plurality of filternetworks'connected to terminalsof saidA Vsequencel switch, said filter networks being selective of the lfrequenciesv peculiar to the dilerent groups of truilks','th`eY cth'erV end of'said networksbeing connected to atest wiperwof the first-selector, whereby said test relay. is operated when said sequenceswitch connects, saidl relay to Aa filter network vwhich permits the telephone system,the com- 8v passage of the Vparticularfrequency from the terminal of said'selector with which said wiper is Vthen in contact.

9. A two-stage selector comprising a first stage switch, apluralityof second stage switches availd ableA to said VVrst stage switch and having outlets in a number of directions, means connected to the outlets of the switches of the'second stage` tofeed back to said iirst stage switch electrical test characteristics indicative of the idle or busy conditioner each of the various groups of outletsrtherefrom, means connected to said iirst stage switch and responsive toV a selective signal or signal-combination for determining from said fed back electrical test characteristics the busy or idle condition of the particular group of outlets from the second stage corresponding to vsaidselective signal or signal combination, and means controlled by said lastmentioned means for causingv said rst stage switch to select an idle second stage switch having an idle outlet in said particular group of outlets. v

10. A two-stage selector, as claimed in claim 9, in which the means responsive to a selective signal or signal combination comprises a marker device adapted to be set inresponse to a selec-v tive signal or signal combination and to mark a Wanted group of Youtlets from `the rst stage and to control the selection of a second stage switchv having an idle `outlet in a desired one of a number of directions. Y

1l. In an automatic telephone system, the combination, according to claim 1, further coinprising means for causingthe second selector to start hunting for the marked group of trunks upon the seizure of said second selector, and

means for stopping said second selector when an idle trunk in the marked group is reached. f FERNAND P. GOHOREL.

References caes in the sie of this patent UNITED sfrAfrEs PATENTS 2,424,585 Simon July 29, 

